Broad molecular weight distribution (MWD) polyolefins may be characterized as containing at least two different molecular weight (MW) polymer fractions. One polymer fraction has a relatively high molecular weight (HMW) relative to the second polymer fraction which has a relatively low molecular weight (LMW). FIG. 2 illustrates a sample of polyethylene product in which the difference in MW of each of the two polymer fractions is relatively large so that each of the two polymer components are clearly identified in the Gel Permeation Chromatogram recorded on such a polymer sample. This type of MWD is required for polyethylene products exhibiting a relatively high density (0.93-0.96 g/cc) and used in manufacturing polyethylene film.
However, a different MWD (illustrated in FIG. 1) is required for polyethylene products exhibiting a lower density range (0.90-0.93 g/cc) in order to reduce the amount of polymer which is extracted with hexane (designated as hexane extractables) which must be less than 6 wt. % so that this type of polyethylene may be used in food packaging applications. For such applications, the relatively LMW polymer component must be somewhat higher in MW so that the hexane extractables test required for food packaging applications may be passed, i.e., less than 6 wt. % of the polymer. In addition, a similar MWD is required for polyethylene products exhibiting a density range of 0.93-0.96 g/cc which may be used in blow molding applications.